1. Field of the Invention
The present invention relates to a display and methods for fabricating the same, and more particularly, to a liquid crystal display and methods for fabricating the same.
2. Description of the Related Art
Liquid crystal displays (LCD) are commonly used for flat panel displays. Owing to dielectric anisotropy and conductive anisotropy of liquid crystal molecules, molecular orientation of liquid crystals can be shifted under an external electronic field, such that various optical effects are produced. The panel structure of an LCD typically comprises two laminated substrates separated by a gap and liquid crystal injected therebetween. Corresponding electrodes on each substrate control the direction and arrangement of liquid crystal molecules.
Referring to FIG. 1A, in addition to the three primary colors pixels, which are red, green, and blue pixels, a white pixel is also provided to increase transmissive or reflective brightness and thus reduce power consumption. Mixed RGBW LCDs, however, suffer from many drawbacks.
Referring to FIG. 1B, a first substrate 100 such as an array substrate is provided. The first substrate 100 comprises a plurality of pixels, each comprising a plurality of sub-pixels.
A plurality of thin film transistors (TFTs) 108 is then formed on the first substrate 100, and each sub-pixel corresponds to a TFT 108. The TFT 108 comprises a gate 102, source 104, and drain 106.
A second substrate 110 opposite to the first substrate 100 is provided. The second substrate 210, preferably is a color filter substrate, comprises a red region provided with a red resist layer R thereon, a blue region provided with a blue resist layer B thereon, a green region provided with a green resist layer G thereon and a white region provided with a transparent resist layer W thereon, wherein each region corresponds to a sub-pixel. Thus, a color filter layer with the mixed RGBW is obtained.
After forming the RGB resist layers, a planarized covering layer 112 is blanketly coated on the second substrate 110 and the gaps between RGB resist layers is thus filled with the covering layer 212, thereby forming the transparent resist layer W. The planarized covering layer 112 is beneficial for subsequent fabrication processes due to its planar surface. Because the RGB resist layers affect surface tension and mechanical action of the covering layer 112, a gap “d” exists in portions of the covering layer 112 corresponding to the white region. Accordingly, a color shift phenomenon such as a yellow shift arises in LCDs.